Step and flash imprint lithography

• US 6,334,960 B1
• Filed: 03/11/1999
• Issued: 01/01/2002
• Est. Priority Date: 03/11/1999
• Status: Expired due to Term

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Willson, Carlton Grant, Colburn, Matthew Earl
• Primary Examiner(s): Markoff, Alexander
• Application Number:
  US09/266,663
• Time in Patent Office: 1,027 Days
• Field of Search: 216/2, 216/44, 216/52, 216/67, 216/72, 216/13
• US Class Current: 216/52
• CPC Class Codes: B29C 2043/025 forming a microstructure, i.e. fine patterning
• CPC Class Codes: B29C 43/003 characterised by the choice of material
• CPC Class Codes: B29C 43/021 characterised by the shape of the surface
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G03F 7/0002 Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping
• CPC Class Codes: H05K 3/061 Etching masks
• CPC Class Codes: Y10S 977/887 Nanoimprint lithography, i.e. nanostamp
• CPC Class Codes: Y10S 977/897 Polymerization

Abstract

A method of forming a relief image in a structure comprising a substrate and a transfer layer formed thereon comprises covering the transfer layer with a polymerizable fluid composition, and then contacting the polymerizable fluid composition with a mold having a relief structure formed therein such that the polymerizable fluid composition fills the relief structure in the mold. The polymerizable fluid composition is subjected to conditions to polymerize polymerizable fluid composition and form a solidified polymeric material therefrom on the transfer layer. The mold is then separated from the solid polymeric material such that a replica of the relief structure in the mold is formed in the solidified polymeric material; and the transfer layer and the solidified polymeric material are subjected to an environment to selectively etch the transfer layer relative to the solidified polymeric material such that a relief image is formed in the transfer layer.

Claims

1. A method of forming a relief image in a structure said method comprising:

covering the substrate with a polymeric transfer layer to provide a continuous, planar surface thereon;

covering the polymeric transfer layer with a polymerizable fluid composition;

contacting the polymerizable fluid composition with a mold having a relief structure formed therein such that the polymerizable fluid composition substantially fills the relief structure in the mold;

subjecting the polymerizable fluid composition to conditions to polymerize polymerizable fluid composition and form a solidified polymeric material therefrom on the transfer layer;

separating the mold from the solid polymeric material such that a replica of the relief structure in the mold is formed in the solidified polymeric material; and

subjecting the transfer layer and the solidified polymeric material to an etching environment to etch solidified polymeric material and to selectively etch the transfer layer relative to the solidified polymeric material to form a relief image in the transfer layer providing patterned access to the substrate.

2. A method according to claim 1, further comprising the step of fabricating a device from the structure, the device selected from the group consisting of a microelectronic device, an information storage device, a printed wiring board, a flat panel display, a micromachine, and a charge couple device.

3. A method according to claim 1, wherein the polymerizable fluid composition comprises an organosilane.

4. A method according to claim 3, wherein the organosilane contains elemental silicon in an amount greater than about 8 weight percent based on the weight of the polymerizable fluid composition.

5. A method according to claim 1, wherein the polymerizable fluid composition includes a reactive pendant group selected from the group consisting of an epoxy group, a ketene acetyl group, an acrylate group, a methacrylate group, and combinations thereof.

6. A method according to claim 1, wherein the transfer layer comprises a material selected from the group consisting of an organic thermoset polymer, a thermoplastic polymer, a polyepoxy, a polyamide, a polyurethane, a polycarbonate, a polyester, and combinations thereof.

7. A method according to claim 1, wherein the mold comprises a material selected from the group consisting of metal, silicon, an organic polymer, a siloxane polymer, borosilicate glass, a fluorocarbon polymer, and combinations thereof.

8. A method according to claim 1, wherein the mold comprises quartz.

9. A method according to claim 1, further comprising the step of treating the mold with a surface modifying agent.

10. A method according to claim 9, wherein said step of treating the mold is carried out by employing a technique selected from the group consisting of a plasma technique, a chemical vapor deposition technique, a solution treatment technique, and mixtures thereof.

11. A method according to claim 9, wherein the surface modifying agent is a fluorocarbon silylating agent.

12. A method according to claim 1, wherein the mold is transparent and wherein said step of subjecting the polymerizable fluid composition comprises subjecting the polymerizable fluid composition to radiation sufficient to polymerize the fluid composition and to form a solid polymeric material.

13. A method according to claim 1, wherein said step of subjecting the transfer layer and the solid polymeric ma rial to an environment comprises subjecting the transfer layer and the solid polymeric material to an environment comprising an argon ion stream, an oxygen-containing plasma, a reactive ion etch gas, a halogenated-containing gas, a sulfur dioxide-containing gas, and combinations thereof.

14. A method according to claim 1, wherein residual material selected from the group consisting of a portion of the polymerizable fluid composition, a portion of the solid polymeric material, and combinations thereof is present subsequent to said step of subjecting the polymerizable fluid composition to conditions to form a solid polymeric material, and said method further comprising the step of subjecting the residual material to conditions such that the residual material is removed.

15. A method according to claim 14, wherein said step of subjecting the residual material occurs prior to said step of subjecting the transfer layer and the solid polymeric material to an environment to selectively etch the transfer layer relative to the solid polymeric material.

16. A method according to claim 14, wherein said step of subjecting the residual material to conditions such that the residual material is removed comprises subjecting the residual material to an environment selected from the group consisting of an argon ion stream, a fluorine-containing plasma, a reactive ion etch gas, and mixtures thereof.

17. A method according to claim 11, wherein said substrate is preformed prior to said step of covering the substrate with a polymeric transfer layer.

18. A method of forming a relief image in a structure said method comprising:

covering the substrate with a polymeric transfer layer to provide a continuous, planar surface thereon;

covering the polymeric transfer layer with a polymerizable fluid composition comprising a silicon-containing material;

contacting the polymerizable fluid composition with a mold having a relief structure formed therein such that the polymerizable fluid composition substantially fills the relief structure in the mold;

subjecting the polymerizable fluid composition to conditions to polymerize polymerizable fluid composition and form a solidified polymeric material therefrom on the transfer layer;

separating the mold from the solid polymeric material such that a replica of the relief structure in the mold is formed in the solidified polymeric material; and

subjecting the transfer layer and the solidified polymeric material to an etching environment to etch solidified polymeric material and to selectively etch the transfer layer relative to the solidified polymeric material to form a relief image in the transfer layer providing patterned access to the substrate.

19. A method according to claim 18, further comprising the step of fabricating a device from the structure, the device selected from the group consisting of a microelectronic device, an information storage device, a printed wiring board, a flat panel display, a micromachine, and a charge couple device.

20. A method according to claim 18, wherein the polymerizable fluid composition comprises an organosilane.

21. A method according to claim 20, wherein the organosilane contains elemental silicon in an amount greater than about 8 weight percent based on the weight of the polymerizable fluid composition.

22. A method according to claim 18, wherein the polymerizable fluid composition includes a reactive pendant group selected from the group consisting of an epoxy group, a ketene acetyl group, an acrylate group, a methacrylate group, and combinations thereof.

23. A method according to claim 18, wherein the transfer layer comprises a material selected from the group consisting of an organic thermoset polymer, a thermoplastic polymer, a polyepoxy, a polyamide, a polyurethane, a polycarbonate, a polyester, and combinations thereof.

24. A method according to claim 18, wherein the mold comprises a material selected from the group consisting of metal, silicon, an organic polymer, a siloxane polymer, borosilicate glass, a fluorocarbon polymer, and combinations thereof.

25. A method according to claim 18, wherein the mold comprises quartz.

26. A method according to claim 18, further comprising the step of treating the mold with a surface modifying agent.

27. A method according to claim 26, wherein said step of treating the mold is carried out by employing a technique-selected from the group consisting of a plasma technique, a chemical vapor deposition technique, a solution treatment technique, and mixtures thereof.

28. A method according to claim 26, wherein the surface modifying agent is a fluorocarbon silylating agent.

29. A method according to claim 18, wherein the mold is transparent and wherein said step of subjecting the polymerizable fluid composition comprises subjecting the polymerizable fluid composition to radiation sufficient to polymerize the fluid composition and to form a solid polymeric material.

30. A method according to claim 18, wherein said step of subjecting the transfer layer and the solid polymeric material to an environment comprises subjecting the transfer layer and the solid polymeric material to an environment comprising an argon ion stream, an oxygen-containing plasma, a reactive ion etch gas, a halogenated-containing gas, a sulfur dioxide-containing gas, and combinations thereof.

31. A method according to claim 18, wherein residual material selected from the group consisting of a portion of the polymerizable fluid composition, a portion of the solid polymeric material, and combinations thereof is present subsequent to said step of subjecting the polymerizable fluid composition to conditions to form a solid polymeric material, and said method further comprising the step of subjecting the residual material to conditions such that the residual material is removed.

32. A method according to claim 31, wherein said step of subjecting the residual material occurs prior to said step of subjecting the transfer layer and the solid polymeric material to an environment to selectively etch the transfer layer relative to the solid polymeric material.

33. A method according to claim 31, wherein said step of subjecting the residual material to conditions such that the residual material is removed comprises subjecting the residual material to an environment selected from the group consisting of an argon ion stream, a fluorine-containing plasma, a reactive ion etch gas, and mixtures thereof.

34. A method according to claim 18, wherein said substrate is preformed prior to said step of covering the substrate with a polymeric transfer layer.